Robust and resilient timing architecture for critical infrastructure

Patent metadata

Field	Value
Publication number	US-2016306048-A1
Application number	US-201514690225-A
Country	US
Kind code	A1
Filing date	Apr 17, 2015
Priority date	Apr 17, 2015
Publication date	Oct 20, 2016
Grant date	—

Abstract

A device for transmitting synchronized timing including a receiver, a transmitter, one or more processors, memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for receiving through the receiver a timing signal comprising first time information that is synchronized to a time standard, determining second time information based at least partially on the first time information, composing a message formatted in accordance with a global navigation satellite system (GNSS) standard, wherein the message comprises the second time information, and transmitting the message through the transmitter on a radio signal having a frequency in the frequency modulation (FM) radio frequency band.

First claim

What is claimed as new and desired to be protected by Letters Patent of the United States is:

1 . A device for transmitting synchronized timing comprising:
a receiver; a transmitter; one or more processors; memory; and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for: receiving through the receiver a timing signal comprising first time information that is synchronized to a time standard; determining second time information based at least partially on the first time information; composing a message formatted in accordance with a global navigation satellite system (GNSS) standard, wherein the message comprises the second time information; and transmitting the message through the transmitter on a radio signal having a frequency in a frequency modulation (FM) radio frequency band.

2 . The device of claim 1 , wherein the time standard is Coordinated Universal Time (UTC).

3 . The device of claim 1 , wherein the synchronization of the first time information to the time standard is accurate to within 10 nanoseconds [goal is 1 nanosecond].

4 . The device of claim 1 , wherein the first time information is independent of a GNSS.

5 . The device of claim 1 , wherein the receiver is configured to receive the timing signal over fiber optic cable from a ground-based time transmitter.

6 . The device of claim 1 , wherein the second time information is synchronized to the time standard and the synchronization is accurate to within 500 nanoseconds [goal is 100].

7 . The device of claim 1 , wherein the message further comprises information based on a location of the device.

8 . The device of claim 1 , wherein the transmitter is configured to simultaneously transmit the message on two radio signals having frequencies in the FM radio frequency band.

9 . The device of claim 1 , further including instructions for encrypting the message prior to transmitting the message through the transmitter.

10 . The device of claim 1 , wherein the message comprises at least one of a pseudorandom noise code, time-of-week information, and clock correction information.

11 . A method comprising:
at an electronic device with a processor, a receiver, and a transmitter:
receiving through the receiver a timing signal comprising first time information that is synchronized to a time standard;
determining second time information based at least partially on the first time information;
composing a message formatted in accordance with a GNSS standard, wherein the message comprises the second time information; and
transmitting the message through the transmitter on a radio signal having a frequency in an FM radio frequency band.

12 . The method of claim 11 , wherein the time standard is UTC.

13 . The method of claim 11 , wherein the synchronization of the first time information to the time standard is accurate to within 10 nanoseconds [goal is 1 nanosecond].

14 . The method of claim 11 , wherein the first time information is independent of a GNSS.

15 . The method of claim 11 , wherein the receiver is configured to receive the timing signal over fiber optic cable from a ground-based time transmitter.

16 . The method of claim 11 , wherein the second time information is synchronized to the time standard and the synchronization is accurate to within 500 nanoseconds [goal is 100].

17 . The method of claim 11 , wherein the message further comprises information based on a location of the device.

18 . The method of claim 11 , wherein the transmitter is configured to simultaneously transmit the message on two radio signals having frequencies in the FM radio frequency band.

19 . The method of claim 11 , further comprising encrypting the message prior to transmitting the message through the transmitter.

20 . The method of claim 11 , wherein the message comprises at least one of a pseudorandom noise code, time-of-week information, and clock correction information.

21 . A receiving device comprising:
a receiver;
a transmitter;
one or more processors;
memory; and
one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for:
receiving through the receiver a radio signal having a frequency in an FM radio frequency band, the radio signal comprising a message formatted in accordance with a GNSS standard;
extracting first time information from the message;
determining second time information based at least partially on the first time information, wherein the second time information is synchronized to a time standard;
generating a timing signal based at least partially on the second time information; and
transmitting the timing signal through the transmitter.

22 . The receiving device of claim 21 , wherein the synchronization of the second time information is accurate to within 10 microseconds relative to the time standard. [goal is 1 microsecond]

23 . The receiving device of claim 21 , wherein the receiver is configured to simultaneously receive two radio signals having frequencies in an FM radio frequency band.

24 . The receiving device of claim 21 , including instructions for decrypting the message.

25 . The receiving device of claim 21 , wherein the message comprises at least one of a pseudorandom noise code, time-of-week information, and clock correction information.

26 . The receiving device of claim 21 , further comprising a second receiver configured to receive a GNSS signal and determine a GNSS time information from the GNSS signal, and further including instructions for:
detecting one or more errors in the radio signal and the GNSS signal; and generating the timing signal based at least partially on the second time information when a GNSS signal error is detected and at least partially on the GNSS time information when a radio signal error is detected.

27 . A receiving method comprising:
at an electronic device with a processor, a receiver, and a transmitter:
receiving through the receiver a radio signal having a frequency in the FM radio frequency band, the radio signal comprising a message formatted in accordance with a GNSS standard;
extracting first time information from the message;
determining second time information based at least partially on the first time information, wherein the second time information is synchronized to a time standard;
generating a timing signal based at least partially on the second time information; and
transmitting the timing signal through the transmitter.

28 . The receiving method of claim 27 , wherein the synchronization of the second time information is accurate to within 10 microseconds relative to the time standard. [goal is 1 microsecond]

29 . The receiving method of claim 27 , wherein the receiver is configured to simultaneously receive two radio signals having frequencies in an FM radio frequency band.

30 . The receiving method of claim 27 , including decrypting the message.

31 . The receiving method of claim 27 , wherein the message comprises at least one of a pseudorandom noise code, time-of-week information, and clock cor

Assignees

• Mitre Corp

Inventors

• Dunn Jeffrey
• Mckenna Sean
• Martin Cynthia E
• Cohen Michael L

Classifications

• G04G7/00 Primary

  Synchronisation (radio-controlled time-pieces G04R) · CPC title

• G04R20/02

  the radio signal being sent by a satellite, e.g. GPS · CPC title

• G01S19/10 Primary

  providing dedicated supplementary positioning signals · CPC title

• G01S19/20

  Integrity monitoring, fault detection or fault isolation of space segment · CPC title